Tuesday, January 24, 2012

New Sample: Report_TrainControlChart

by AD Tejpal

This sample db demonstrates time distance charting of trains on a double line route. Time axis, covering 24 hours is depicted horizontally, while various railway stations are displayed along the vertical axis. Vertical lines across chart area identify half hour time intervals. For convenient legibility, time lines at two hour intervals have darker shade.

Positioning of stations is in proportion to their respective distance from terminal station as compared to overall length of route. Major stations have adequate loop lines, while the minor ones have no facility for overtaking.

Each pair of trains is assigned a distinct color (in table T_Trains). T1/T2 (Red) is a slow train, stopping at all stations. T3/T4 (Blue) is faster and stops only at major stations en-route. T5/T6 (Green) is a super fast pair, stopping at only at some of the major stations en-route. Halts of slower trains are devised in such a manner as to permit un-impeded overtake by faster ones. Two local trains (L1 and L2) performing multiple U trips are also demonstrated. Start and end points of each train have been made prominent by placement of a marker (a small circle - looks like a big dot) in a color matching that of the train in question.

Train control chart can be viewed in three alternative styles as follows, depending upon user's choice via option group:

(a) Whole route at a glance.

(b) Zoomed view of first half of route.

(c) Zoomed view of second half of route.


(a) If more stations get added (in table T_Stations), proportionate inter-station spacing in the chart will get adjusted automatically so as to suit the available chart height.

(b) Chart height is set as 8100 twips via report level constant mTotChartHt. This is found to work fine in Access 2003 on Win XP (Paper size: A4, Default printer: HP Laserjet M1005). If, depending upon local set up, it is found that the report tends to spill over beyond one page, the value of this constant can be adjusted downwards suitably. For complete chart to be depicted, it is important that report (R_TrainControlChart) remains confined to a single page.

Version: Access 2000 file format.   References: DAO 3.6

You can find the sample here: http://www.rogersaccesslibrary.com/forum/topic581_post599.html


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